Antenna



Nov. 29, 1949 P. A. GUARINO ET AL 2,489,287

ANTENNA Filed March 26, 1946 2 Sheets-Sheet 1 mmvroas EANTHONY GUARINODAvD WILLIAMS ATTORNEY Nov. 29, 1949 P. A. GUARINO ET AL 8 ANTENNA FiledMarch 26, 1946 2 Sheets-Sheet 2 INVENTORS P. ANTHONY GUARINO DAVIDWILLIAMS ATTORNEY IIIIIIIIIIIIIIIIIIIIIIIIIIIIIII Patented Nov. 29, 1949ANTENNA Pasquale Anthony Guarino, Cleveland, Ohio, and David Williams,Washington, D. 0.

Application March 26, 1946, Serial No. 657,311

6 Claims. (Cl. 250---33..65)

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) This invention relates to antenna systems and moreparticularly, to a single antenna structure to provide omni-directional,non-polarized recep tion of radiant energy over a broad band offrequencies.

In a radio search receiver it is desirable for many purposes to receiveany transmission of radiant energy without limitations because of itsfrequency, type of polarization, or position of source relative to thereceiving antenna. To attempt this coverage with ordinary means wouldrequire numerous antennas: different antennas for each small change offrequency, additional antennas in each frequency band for differenttypes of polarization, and additional antennas in each of these twoclasses to permit reception through 360. To accomplish this purpose witha single antenna structure provides a great economy of space, material,and expense, and will permit installations hitherto prohibited byinsufiicient space.

An object of this invention is to provide an antenna system of simpleconstruction capable of omni-directional, non-polarized reception over awide band of frequencies.

Another object of this invention is to provide an antenna system ofsimple construction capable of omni-directional, non-polarized receptionover a wide band of frequencies while maintaining satisfactory standingwave ratio and resistance characteristics (and more particularly,maintaining a standing wave ratio of less than two to one over a majorportion of its frequency range).

Another object of this invention is to provide an antenna system ofsimple construction capable of omni-directional, non-polarized receptionover a wide band of frequencies, which although designed for receivingpurposes, meets the usual requirements for transmitting antennas.

Another object of this invention is to provide an antenna system ofsimple construction capable of omnidirectional, non-polarized receptionover a wide band of frequencies, directly connectable by a transmissionline to an unbalanced receiver means without requiring matchingtransformers or other balancing devices.

Another object of this invention is to provide an antenna ground plawhich may combined with a suitable radi... W element so as to constitutean Omani-directional, non-polarized, antenna system.

Another object of this invention is to provide an antenna ground wh maybe so incorporated with a suitable radiating element as to constitute awide-band, omni-directional, nonpolarized antenna system.

Another object of this invention is to provide an antenna ground planewhich may be so incorporated with a suitable radiating element as toconstitute a wide-band, non-polarized antenna system.

Other objects and features of novelty of the invention will be madeapparent by the following description and the annexed drawings, it beingunderstood that such description and drawings are merely illustrative ofthe invention and impose no limitations thereon.

In the drawings:

Figs. 1 and 2 are side and top elevational views respectively of onetypical embodiment of the invention;

Fig. 4 is a cross-sectional view taken thru line 44 of Fig. 3 andshowing the antenna radiating element and the support therefor, and

Fig. 3 is an underside view of the antenna ground plane.

Briefly, the omni-directional, non-polarized, wide band antenna providedby this invention comprises a ground plane in combination with asuitable radiating element. The ground plane is tilted at an anglesomething less than with respect to the vertical and the radiatingelement is supported with respect to the ground plane in such a mannerthat its axis makes an angle of something less than 90 relative to theground plane.

Referring, now, in particular to Figs. 1 and 2 of the drawings, it isseen that the ground plane comprises a series of co-planar, equalangularly disposed reflecting rods ll through I! radiating from avertex. These reflecting rods are electrically secured to a suitablemetallic base-plate member indicated at 5, Fig. 2, and are supported ina plane tilted at an angle 23 with respect to the vertical bycylindrical member 9. This departure from the vertical is necessary toaccomplish nonpolarized operation. For purposes of permittingomni-directional reception or transmission, the reflecting rods Iithrough ii are disposed about the vertex through some angle less thanFor the same reason, the base plate 5 is cut away as indicated at 25 inFig. 2.

The radiating element as shown in Figs. 1 and 2 comprises in itspreferred form, a conical shaped metallic member 6 which is terminatedat its base in a hemispherical section 26. The conical radiating element5 is so disposed with respect to the reflecting rods ll through l1 thatits axis 20 intersects the vertex of the reflecting rods and lies in aplane perpendicular to both the plane of the reflecting rods and theplane which bisects the angle between the end reflecting rods II and I1.Additionally, it is tilted in this plane so that its axis 20 makes anangle therein (shown as angle 22 in Fig. 4) of something less than 90with respect tothe plane of the reflecting rods.

Referring to Fig. 4, the apex of the cone is terminated in the centerconductor of a connector 1 for the coaxial transmission line shown at 21in Fig. 1. The connection for the outer contact of this connector isshown at'8', and is electrically joined to the ground plane through theconical conductor shown at 48 and. the base plate 5.-

This coaxial cable serves to connect the antenna system to a transmitteror receiver means and may be directly connected without the necessity ofmatching or balancing devices.

None of the physical dimensions of this invention is especiallycritical. Except in respect to back pick up; the size of the groundplane constitutes a limiting factor only at the lower extremity of thefrequency range. It should have a radial dimension greater thanone-quarter wave length for the low end of the frequency band to becovered. For electri al purposes the ground plane becomes larger as thefrequency increases. For this reason even the base plate 5 will becomelarge enough to interfere with back pick up at the higher frequencies.The cone is of a length approximating something greater than one-eighthwave length at the low end of its frequency range and approximatingthree halves wave length at its high end. Supporting the conicalradiating element midway between its base and its apex such as by thecylindrical insulating shell is extends its frequency range to a higherlimit than otherwise possible.

In a specialized case an antenna constructed according to the followingspecification was found to operate very satisfactorily over a frequencyband extending from 300 Inc. to 3000 me.

With reference to Fig. 4, the radius of curvature of the hemisphericalsection 26 of the control radiating element was set at 6%". The diameterof the cone base was set at 6.8". The cone was tilted. at an. angle 22of 60 to the ground plane and is affixed thereto by a nonconductingmember l9 supporting it about its center to prevent irregularities withthe dielectric constant about the apex. For the same reason thesupporting plugs shown at Zia and 2 lb are made of insulation with adielectric constant approaching that of air.

With reference to Fig. 4, the base plate 5 has for its larger dimensiona radius of 3" and for its smaller dimension, a radius of 1 inches. Thereflecting rods llll are in length and aflixed' (brazed for example) tothe periphery of the larger dimension of the base plate, establishing anoverall distance of 18" from the vertex to the ends of the reflectingrods.

The displacement of the ground plane from the vertical as shown by theangle 23 in Fig. 1 is 45. The antenna system was connected by a 50 ohmcoaxial transmission line shown at 21 in Fig. 1 to the input of anunbalanced receiver.

Although we have shown and described only a limited and specificembodiment of the present invention we are fully aware of the manymodificationsv possible thereof. Therefore this invention is not to belimited except insofar as is necessitated by the spirit of the prior artand the scope of the appended claims.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

What is claimed is:

1.. An antenna, comprising a radiating element and a ground planereflector surface, said ground plane reflector surface comprising aseries of radially extending reflecting rods lying in a plane which istilted at an angle less than with respect to the vertical, and saidradiating element being. sotil'ted with respect to said ground planereflector surface that it makes an angle of something less than 90therewith.

2. An antenna, comprising a radiating element symmetrically arrangedabout a longitudinal axis and a ground plane reflector surface, saidground plane reflector surface comprising a series of reflecting rodsextending radially from a vertex and lying in a plane which is tilted atan angle less. than 90 with respect to the vertical, said reflectingrods being so arranged that the angle between the extreme end rods ofsaid series is less than 180, and said radiating element being sodisposed that its axis intersects the vertex of said reflecting rods andso tilted in a plane whichv is perpendicular to. both the plane of thereflector rods and. aplane which bisects the angle between the said endreflecting rods that its axis. makes an angle therein of something lessthan 90 with respect to the plane of the reflector rods.

, 3. An antenna, comprising a radiating element symmetrically arranged.about a longitudinal axis and a ground plane reflector surface, saidground plane reflector surface comprising a series of reflecting rodsextending radially from a vertex and lying in a plane which is tilted atan angle of 45 with respect to the vertical, said reflecting rods beingso arranged that the angle between the extreme end rods of said seriesis and said radiating element being. so disposed that its axisintersects the vertex of. said reflecting rods and so tilted. in a planewhich is perpendicular to both the plane of the reflector rods and aplane which bisects the angle between the said end reflecting rods thatits axis makes an angle of 60 therein with respect to the plane of thereflector rods.

4. An antenna, comprising a conical radiating element and a ground planereflector surface, said ground plane reflector surface comprising aseries of radially extending reflecting rods the plane of which istilted at an angle less than 90 with respect to the vertical, and saidradiating element being so tilted with respect to said ground planereflector. surface that it makes an angle something less than 90therewith.

5. An antenna, comprising a conical radiating element symmetricallyarranged about a longitudinal axis and a ground plane reflector surface,said ground plane reflector surface comprising a series of reflectingrods extending radially from a vertex and lying in a plane which istilted at an angle less than 90 with respect to the vertical, saidreflecting rods being so arranged that the angle between the extreme endrods of said series is less than and said radiating element being sodisposed that its axis intersects the vertex of said reflecting rods andso tilted in a plane which is perpendicular to both the plane of thereflecting rods and a plane which bisects the angle between the said endreflecting rods that its axis makes an angle something less than 90 withrespect to the plane of the reflector rods.

an angle of 45 with respect to the vertical, said reflecting rods beingso arranged that the angle between the extreme end rods of said seriesis 150, and said radiating element being so disposed that its axisintersects the vertex of said reflecting rods and. so tilted in a planewhich is perpendicular to both the reflector rods and a plane whichbisects the angle between the said end REFERENCES CITED The followingreferences are of record in the file of this patent:

Niunber reflecting rods that its axis makes an angle of 15 60 thereinwith respect to the plane of the reflector rods.

P. ANTHONY GUARINO. DAVID WILLIAMS.

Number 5 UNITED STATES PATENTS Name Date Fessenden Mar. 8, 1904 LudeniaMar. 27, 1934 Ponte Jan. 7, 1936 Hooven Oct. 25, 1938 Buschbeck Mar. 19,1940 Aubert Dec. 30,1941 Granquist Dec. 21, 1943 FOREIGN PATENTS CountryDate Germany July 7, 1937

